TY - JOUR
T1 - Influence of Pressure on the Intramolecular Spin Exchange in a Short Imidazolium-Nitroxide Biradical
AU - Mladenova-Kattnig, Boryana
AU - Grampp, Günter
AU - Kokorin, Alexander I.
PY - 2017/4/1
Y1 - 2017/4/1
N2 - A short-chain imidazoline-type nitroxide biradical R5 NO–CH=N–N=C(CH3)–R5 N, B2, with nitroxide rings R5 N and R5 NO as 1-oxyl-2,2,5,5-tetramethyl-3-imidazoline and 1-oxyl-2,2,5,5-tetramethyl-3-N-oxide imidazoline, respectively, has been studied using X-band electron paramagnetic resonance (EPR) spectroscopy in CH3CN solutions at variable temperature T and pressure P. Changes of the solution viscosity on the intramolecular electron spin exchange in B2 is characterized by calculating the value of the exchange integral |J/a|, where a denotes the 14N hyperfine splitting (hfs) constant. It is revealed that the intramolecular dynamics in B2 do not follow the Debye–Stokes–Einstein law, while the Arrhenius dependence is fulfilled. Probable reasons of such behavior are discussed.
AB - A short-chain imidazoline-type nitroxide biradical R5 NO–CH=N–N=C(CH3)–R5 N, B2, with nitroxide rings R5 N and R5 NO as 1-oxyl-2,2,5,5-tetramethyl-3-imidazoline and 1-oxyl-2,2,5,5-tetramethyl-3-N-oxide imidazoline, respectively, has been studied using X-band electron paramagnetic resonance (EPR) spectroscopy in CH3CN solutions at variable temperature T and pressure P. Changes of the solution viscosity on the intramolecular electron spin exchange in B2 is characterized by calculating the value of the exchange integral |J/a|, where a denotes the 14N hyperfine splitting (hfs) constant. It is revealed that the intramolecular dynamics in B2 do not follow the Debye–Stokes–Einstein law, while the Arrhenius dependence is fulfilled. Probable reasons of such behavior are discussed.
UR - http://www.scopus.com/inward/record.url?scp=85012880161&partnerID=8YFLogxK
U2 - 10.1007/s00723-017-0865-1
DO - 10.1007/s00723-017-0865-1
M3 - Article
AN - SCOPUS:85012880161
SN - 0937-9347
VL - 48
SP - 327
EP - 334
JO - Applied Magnetic Resonance
JF - Applied Magnetic Resonance
IS - 4
ER -